Canadian Curler Cusses Out Swedish Opponent After Cheating Accusations, Video

3:20 PM PT -- Canada has released a statement in the aftermath of the incident ... stating in part, "Curling Canada fully supports fair play, respect and sportsmanship, values that are fundamental to our sport."

Marc Kennedy has also apologized for using the language he did during the tense moment.

Canadians might generally be known for their polite manners, but those apparently didn't travel with one curling competitor to Milan for the Winter Olympics ... because he threw some NSFW language at an opponent.

Marc Kennedy -- a four-time Olympian for The Great White North -- got into a shouting match with Sweden's Oskar Eriksson during a tense match Friday.

Eriksson claimed Kennedy -- the athlete throwing the rock in curling -- was touching it again after initially releasing it ... a violation of the rules.

The Canadian flew into a rage when the Swede called his integrity into question ... telling his opponent, "I haven't done it once. You can f*** off."

Eriksson chirped back, saying he could show Kennedy the receipts after the match ... which sparked more profanity from Kennedy.

After Canada won the match 8-6, Kennedy told a reporter he blew up because he didn't like "being accused of cheating after 25 years on tour and four Olympic Games. I told him where to stick it."

Kennedy has won two Olympic medals, including gold in 2010. Eriksson is no rookie ... he has four medals and won gold in 2022.

BTW ... officials didn't call a foul on Kennedy -- but many online feel he may have double-touched the stone. Tell us what you think by voting above.